Sony sa wp 780 service manual
This is the 14 pages manual for sony sa wp 780 service manual.
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Extracted text from sony sa wp 780 service manual (Ocr-read)
Page 1
2 SA-WP780 SAFETY CHECK-OUT After correcting the original service problem, perform the following safety check before releasing the set to the customer: Check the antenna terminals, metal trim, metallized knobs, screws, and all other exposed metal parts for AC leakage. Check leakage as described below. LEAKAGE TEST The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed metal part having a return to chassis, must not exceed 0.5 mA (500 microamperes.). Leakage current can be measured by any one of three methods.1. A commercial leakage tester, such as the Simpson 229 or RCA WT-540A. Follow the manufacturers instructions to use these instruments. 2. A battery-operated AC milliammeter. The Data Precision 245 digital multimeter is suitable for this job. 3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated AC voltmeter. The limit indication is 0.75 V, so analog meters must have an accurate low-voltage scale. The Simpson 250 and Sanwa SH-63Trd are examples of a passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2 V AC range are suitable. (See Fig. A) Fig. A. Using an AC voltmeter to check AC leakage. 1.5 k Ω 0.15 µF AC voltmete r (0.75 V) To Exposed Metal Parts on Set Earth Ground SAFETY-RELATED COMPONENT WARNING!! COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PA RT NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY. A TTENTION AU COMPOSANT AYANT RAPPORT À LA SÉCURITÉ! LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE 0 SUR LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE REMPLACER CES COM- POSANTS Q UE PAR DES PIÈCES SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
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3 SA-WP780 SECTION 1 DIAGRAMS Note on Printed Wiring Boards: - X : parts extracted from the component side. - a : Through hole. - : P attern from the side which enables seeing. - Indication of transistor. Note on Schematic Diagrams: - All capacitors are in µF unless otherwise noted. (p: pF) 50 WV or less are not indicated except for electrolytics and tantalums. - 2 : nonflammable resistor. - 5 : fusible resistor. - All resistors are in Ω and 1/4 W or less unless otherwise specified. - C : panel designation. - A : B+ Line. - B : B– Line. -V oltages and dc with respect to ground under no-signal conditions. no mark : Power on -V oltages are taken with a VOM (Input impedance 10 M Ω). V oltage variations may be noted due to normal production tolerances. - Signal path. F : A UDIO -A bbreviation AR : Argentine model AU S: Australian model CND : Canadian model E51 : Chilean and Peruvian models RU : Russian model SP : Singapore model SP6 : Singapore and Malaysia models THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS. (In addition to this, the necessary note is printed in each block.) Note: The components identi- fied by mark 0 or dot- ted line with mark 0 are critical for safety. Replace only with part n umber specified. Note: Les composants identifiés par une marque 0 sont cri- tiques pour la sécurité. Ne les remplacer que par une piéce portant le numéro spécifié. - Circuit Boards Location C B These are omitted. E Q B These are omitted. CE B These are omitted. CE Q INPUT CONTROL board SWITCH board LED board MAIN board POWER TRANS board Ve r. 1.3